Validation of wind-driven rain module for HAM-tools

This study is a continuation of previous research carried out to improve the hygrothermal analysis capabilities of the readily available HAM-Tools building simulation software. Previous study intended to improve the program by adding a wind driven rain (WDR) module using the semi-empirical model from ASHRAE 160P. However, further verification of the model was needed. In this study, the WDR module’s verification process was corrected and compared to WUFI simulation. The module was then validated by comparing its results with field measurements. The results indicated that the newly designed HAM-Tools WDR module have good agreement with field measurements. HAM-Tools with added WDR module is then used to study the hygrothermal responses of wood-frame wall with WDR amount calculated using different averaging techniques of high resolution meteorological data. It was concluded that in climates with high rainfall, it is best to use high resolution data (at least 10 minutes) for hygrothermal simulations.

Validation of wind-driven rain module for HAM-tools

This study is a continuation of previous research carried out to improve the hygrothermal analysis capabilities of the readily available HAM-Tools building simulation software. Previous study intended to improve the program by adding a wind driven rain (WDR) module using the semi-empirical model from ASHRAE 160P. However, further verification of the model was needed. In this study, the WDR module’s verification process was corrected and compared to WUFI simulation. The module was then validated by comparing its results with field measurements. The results indicated that the newly designed HAM-Tools WDR module have good agreement with field measurements. HAM-Tools with added WDR module is then used to study the hygrothermal responses of wood-frame wall with WDR amount calculated using different averaging techniques of high resolution meteorological data. It was concluded that in climates with high rainfall, it is best to use high resolution data (at least 10 minutes) for hygrothermal simulations.

A Unified, One Fluid Model for the Drag of Fluid and Solid Dispersals by Permeate Flux towards a Membrane Surface

The drag of dispersals towards a membrane surface is a consequence of the filtration process. It also represents the first step towards the development of the problem of fouling. In order to combat membrane fouling, it is important to understand such drag mechanisms and provide a modeling framework. In this work, a new modeling and numerical approach is introduced that is based on a one-domain model in which both the dispersals and the surrounding fluid are dealt with as a fluid with heterogeneous property fields. Furthermore, because of the fact that the geometry of the object assumes axial symmetry and the configuration remains fixed, the location of the interface may be calculated using geometrical relationships. This alleviates the need to define an indicator function and solve a hyperbolic equation to update the configuration. Furthermore, this approach simplifies the calculations and significantly reduces the computational burden required otherwise if one incorporates a hyperbolic equation to track the interface. To simplify the calculations, we consider the motion of an extended cylindrical object. This allows a reduction in the dimensions of the problem to two, thereby reducing the computational burden without a loss of generality. Furthermore, for this particular case there exists an approximate analytical solution that accounts for the effects of the confining boundaries that usually exist in real systems. We use such a setup to provide the benchmarking of the different averaging techniques for the calculations of properties at the cell faces and center, particularly in the cells involving the interface.

Computational Simulation of Spontaneous Liquid Penetration and Depression Between Vertical Parallel Plates

A computational fluid dynamics model is developed to study the dynamics of meniscus formation and capillary flow between vertical parallel plates. An arbitrary Lagrangian–Eulerian approach is employed to predict and reconstruct the shape of the meniscus with no need to employ implicit interface tracking schemes. The developed model is validated by comparing the equilibrium capillary height and meniscus shape with those predicted by available theoretical models. The model was used to predict the capillary flow of water in hydrophilic (silver) and hydrophobic (Teflon) vertical channels with wall spacings ranging from 0.5 mm to 3 mm. It is shown that the computational model accurately predicts the capillary flow regardless of the channel width, whereas the theoretical models fail at relatively large wall spacings. The model captures several important hydrodynamic phenomena that cannot be accounted for in the theoretical models including the presence of developing flow in the entrance region, time-dependent formation of the meniscus, and the inertial effects of the liquid in the reservoir. The sharp interface tracking technique enables direct access to the flow variables and transport fluxes at the meniscus with no need to use averaging techniques.